Field
This invention relates to a wavelength-multiplexing optical communication module which performs communication by wavelength-multiplexing a plurality of optical signals differing in wavelength.
Background
A wavelength-multiplexing optical communication module transmits, by using optical components such as optical lenses, wavelength selecting filters and a reflecting mirror, signal lights emitted from a plurality of light sources. The optical lenses are fixed on a substrate with a joint material. The arrangement for wavelength-multiplexing the lights emitted from the plurality of light sources and outputting the multiplexed light to an external optical transmission path requires fixing the optical lenses with high position accuracy.
A conventional wavelength-multiplexing optical communication module is known which has grooves in lattice form provided around each of portions on which optical lenses are mounted to prevent interference between pieces of a resin adhesive for fixing the optical lenses (see, for example, JP 2014-102498, hereinafter Patent Literature 1).
In the wavelength-multiplexing optical communication module described in Patent Literature 1, however, the peripheral shapes of pieces of the resin adhesive applied cannot be uniformly formed and there is, therefore, a possibility of the shape of each piece of the resin adhesive being asymmetric with respect to the position of the optical lens disposed on the optical path. In such a case, because stress acting on the optical lens is asymmetric when the resin adhesive cures and shrinks, a misalignment of the optical lens occurs during curing of the resin adhesive and the optical lens cannot be fixed with high positional accuracy.